In my copending and now abandoned application Ser. No. 046,040 filed June 6, 1979 I disclose a bag-making machine wherein a synthetic-resin tube whose leading end has been closed at a first top seam is conveyed longitudinally to a position inside a fixed punching station. A piece of this tube is cut off at the first top seam to leave top-seam portions defining handles and forming a filling opening, and at the same time the tube is formed downstream with a pair of parallel and spaced-apart seams. The downstream seam of this pair constitutes the bottom seam of the bag and the other seam of the pair constitutes the top seam of the next bag to be produced. The tube is cut across between these seams and is tucked between its upstream and downstream ends into a secondary conveyor which transports it away transverse to the normal transport direction to deposit it, folded in half, on top of a stack of such bags.
Such an arrangement is highly efficient at producing extremely useful shopping bags of the so-called undershirt type having a pair of integral handle loops. Although my earlier application envisages depositing the bags directly onto a stack, it has been found that this method is not always satisfactory. Mainly the bags are cumbersome to handle, even if folded in half, so that they frequently form a relatively messy stack in the box. What is more the bags when always stacked in the same orientation form a stack whose top normally tips considerably in one direction due to the different thicknesses of the various parts of the bags. Furthermore this arrangement does not lend itself to an automatic filling of shipping cartons with the bags without operator supervision.